Rigid Piston Valve Incorporating a Solenoid

ABSTRACT

A rigid piston assembly for use in a conventional flush valve includes a rigid piston and a solenoid configured to fixedly engage within the valve body. A flush valve for a plumbing fixture as well as a method of retrofitting a piston valve into a diaphragm flush valve body which includes a rigid piston and solenoid configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/273,066, filed Sep. 22, 2016, which is a continuation of U.S. patentapplication Ser. No. 14/955,567, filed Dec. 1, 2015, now U.S. Pat. No.9,481,989, which is a continuation of U.S. patent application Ser. No.13/866,550, filed Apr. 19, 2013, now U.S. Pat. No. 9,228,662, whichclaims the benefit of U.S. Provisional Patent Application No. 61/636,174filed on Apr. 20, 2012, the entire disclosures of each of which arehereby incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to flush valves and, inparticular, to a rigid piston with a solenoid for use in a flush valve.

Description of Related Art

Valves are used throughout many fluid transfer systems and in variousapplications, such as in the transfer and control of water conduitsystems, and, in particular, in connection with plumbing fixtures inboth residential and commercial settings. For example, flush valves aretypically used for control and operation of toilets, urinals, and thelike, such that when a user actuates a handle, water flows through theflush valve into a basin portion and out the drain.

A common type of flush valve is a diaphragm flush valve. Such adiaphragm flush valve is disclosed in U.S. Pat. No. 4,327,891 to Allenet al., herein incorporated by reference. The Allen patent discloses theuse of a diaphragm in a flush valve, where the diaphragm is made ofmolded rubber and serves to effectuate the flow of water from a waterinlet, through the valve, and to a water outlet. Further, the Allenpatent sets forth various components and sub-components of aconventional flush valve.

Such diaphragm flush valves have several drawbacks. For example, therelatively small by-pass orifice positioned in the diaphragm can becomeclogged with debris, which prevents water from flowing into an upperchamber located in the flush valve. This causes the flush valve toremain open, resulting in constant water flow. In addition, the flushingcycle of the diaphragm flush valve takes approximately seven seconds tocomplete, depending upon the flow rates and pressure of the waterentering the valve, due to the design of the diaphragm of the flushvalve. Since an upper chamber fills slowly, the valve is slowly“shutting off”. Therefore, a significant amount of water is wastedthrough the trap and sewer line during the sealing process of the valve.Yet another drawback is that conventional diaphragm flush valves areimpacted at water pressures below 35 psi, since sealing of the valvebased on the water pressure against the diaphragm is difficult with suchlower water pressure. A need, therefore, exists for a valve replacementelement that can effectively be retrofitted into a flush valve that doesnot have the drawbacks associated with conventional diaphragm flushvalves. A further need exists for a flush valve having improved sealingfeatures. Further still, it would be desirable to incorporate a solenoidinto the flush valve for electronic operation.

SUMMARY OF THE INVENTION

In accordance with one embodiment, a rigid piston assembly is used as areplacement element in a flush valve having a valve body with a fluidinlet, a fluid outlet, an outer cover, and a handle member. The rigidpiston assembly includes a rigid piston with a central opening and aby-pass orifice. The rigid piston is mounted within the valve body. Therigid piston can further include guide members that maintain thealignment of the rigid piston within the valve during operation as wellas a flow ring that gauges the amount of water to be flushed duringoperation.

An adapter may be attached to the central opening of the rigid piston. Acap may be connected to the valve body at an end opposite the fluidoutlet. The cap may have a hollow stem that extends from a centralopening in the cap. The hollow stem can engage the adapter. A sealingcomponent may be placed into the valve body forming a seal between thecap and the valve body.

A piston seal having a by-pass orifice can be fixedly engaged to therigid piston and sealingly engaged to the valve body near an entrance ofthe fluid outlet. The piston seal can have an annular skirt that isadapted to extend out toward the cap and form a seal with the cap. Therigid piston assembly can also include a retaining ring having a by-passorifice. The retaining ring can be fixedly engaged to the piston seal.The retaining ring can include a plurality of channels.

A by-pass device having a body with a first end, a second end, and apassageway located within the body can be placed through the by-passorifices of the rigid piston, the piston seal, and the retaining ring,thereby establishing fluid communication between the fluid inlet and anupper chamber formed between the rigid piston and the cap. When theupper chamber is relieved of pressure, fluid from the fluid inlet forcesthe rigid piston to axially move in a direction opposite the fluidoutlet permitting fluid flow through the fluid outlet.

The rigid piston assembly can further include a fitting having a firstend and a second end. The first end of the fitting can be connected tothe cap, and a solenoid can be connected to the second end. A flowrestricting element can be used to control the flow of water. Aninfrared sensor and a radio frequency chip can also be used with therigid piston assembly. Further, a cover may be attached to the openingpreviously occupied by a handle member.

In accordance with another embodiment, a method of retrofitting a rigidpiston into a flush valve having a diaphragm assembly generally includesremoving the outer cover from the valve body, removing the diaphragmvalve assembly from the valve body, removing the handle member assembly,inserting a rigid piston into the valve body, incorporating an adapterinto the rigid piston, attaching a cap to the valve body at an endopposite the fluid outlet, inserting a first end of a fitting into thecap, and attaching a solenoid to the second end of the fitting. Therigid piston includes a piston seal attached to a portion of the rigidpiston and a by-pass device positioned inside by-pass orifices locatedin the rigid piston and the piston seal. The rigid piston can alsoinclude a retaining ring. The retaining ring can have a by-pass orificeand the by-pass device can also be adapted to fit inside the by-passorifice of the retaining ring. A flow restricting element, infraredsensor, and/or radio frequency chip can also be incorporated into theflush valve. Further, a cover may be attached to the opening previouslyoccupied by a handle member. The method can further include placing asealing component between the cap and valve body.

In accordance with yet another embodiment, a flush valve for a plumbingfixture includes a fluid inlet in fluid communication with a fluidsource, a fluid outlet in fluid communication with a plumbing fixture, acap positioned at an end opposite the fluid outlet, a piston valve forregulating fluid flow between the fluid inlet and the fluid outlet, afitting having a first end and a second end where the first end of thefitting is attached to the cap, and a solenoid connected to the secondend of the fitting. The flush valve can also include an infrared sensorand a radio frequency chip.

The piston valve includes a rigid piston with a central opening and aby-pass orifice. The rigid piston can further include guide members thatmaintain the alignment of the rigid piston within the valve duringoperation as well as a flow ring that gauges the amount of water to beflushed during operation. An adapter may be attached to the centralopening of the rigid piston.

A piston seal having a by-pass orifice is fixedly engaged to the rigidpiston and sealingly engaged to the valve body near an entrance of thefluid outlet. The piston seal can have an annular skirt that is adaptedto extend out toward the cap and form a seal with the cap. The flushvalve can also include a retaining ring. The retaining ring can includea plurality of channels.

A by-pass device having a body with a first end, a second end, and apassageway located within the body can be positioned inside the by-passorifices of the rigid piston, the piston seal, and the retaining ring.The flush valve can also include a sealing component that forms a sealbetween the cap and the valve body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional elevational view of an assembled diaphragmflush valve according to the prior art.

FIG. 2 is an exploded perspective view of the diaphragm flush valveaccording to FIG. 1.

FIG. 3 is an exploded perspective view of one embodiment of a flushvalve according to the present invention.

FIG. 4 is an exploded perspective view of one embodiment of a flushvalve according to the present invention.

FIG. 5A is a cross-sectional elevational view of a flush valve in anon-activated state according to the present invention.

FIG. 5B is a cross-sectional elevational view of the flush valve of FIG.5A in an activated state according to the present invention.

FIG. 5C is a cross-sectional elevational view of the flush valve of FIG.5A during a flushing event according to the present invention.

FIG. 6 is a cross-sectional bottom view of the flush valve according tothe present invention.

FIG. 7 is a bottom view of a retaining ring according to one embodimentof the present invention.

FIG. 8 is a cross-sectional elevational view of a by-pass deviceaccording to the present invention.

FIG. 9 is a top view of a retaining ring according to one embodiment ofthe present invention.

FIG. 10 is a bottom view of the retaining ring of FIG. 9 according tothe present invention.

FIG. 11 is a bottom isometric view of the retaining ring of FIG. 9according to the present invention.

FIG. 12 is a top isometric view of the retaining ring of FIG. 9according to the present invention.

FIG. 13 is a bottom perspective view of retaining ring of FIG. 9attached to a piston seal according to the present invention.

DESCRIPTION OF THE INVENTION

For purposes of the description hereinafter, spatial orientation terms,if used, shall relate to the referenced embodiment as it is oriented inthe accompanying drawing figures or otherwise described in the followingdescription. However, it is to be understood that the embodimentsdescribed hereinafter may assume many alternative variations andembodiments. It is also to be understood that the specific devicesillustrated in the accompanying figures and described herein are simplyexemplary and should not be considered as limiting.

As shown in FIG. 1, a conventional flush valve 2 has a general hollowvalve body 10 which includes a fluid inlet 12, a fluid outlet 14, and ahandle coupling connection 16. The top of the valve body 10 is closed byan outer cover 18 and an inner cover 20. The inlet portion of the valveis separated from the outlet portion by an outlet bore 22 which isattached to the inside of the valve body 10. A main valve seat 24 isformed on the top of the outlet bore 22.

The valve is actuated by an operating handle 26 which is fastened to thevalve body 10 by means of a coupling nut 28. The handle 26 is connectedto a plunger 30 which extends to the interior portion of the valve body10. The plunger 30 is guided and supported by a bushing 32 and restoredby a spring 34. A rubber sealing cap or packing 36 is snapped on the endof bushing 32 and prevents leakage outward from the handle opening.

The main valve seat 24 is normally closed by a flexible rubber diaphragm38. The flexible rubber diaphragm 38 extends across the valve body 10and defines an upper chamber 40. The flexible rubber diaphragm 38includes a by-pass hole 42 which provides fluid communication betweenthe inlet side of the valve and the upper chamber 40. A filter 44 may beprovided thereover to prevent clogging of the by-pass hole 42.

The flexible rubber diaphragm 38 is attached at its outer edge to thevalve body 10. The outer cover 18 clamps the flexible rubber diaphragm38 to the valve body 10. The center of the flexible rubber diaphragm 38has an opening which allows fluid communication between the upperchamber 40 and the fluid outlet 14. A relief valve shown generally at 46is attached to the flexible rubber diaphragm 38 and normally closes theopening at the center of the flexible rubber diaphragm 38. The reliefvalve 46 includes a guide portion 48 having wings 49. The wings 49 fitclosely against the inside diameter of the outlet bore 22. The guideportion 48 also has a lip 50. The lip 50 supports a collar 52. Therelief valve 46 includes a clamping member 54 which is threadablyengaged with the guide portion 48. The clamping member 54 clamps theinner edge of the flexible rubber diaphragm 38 between the clampingmember 54 and the collar 52 to form a seal. The clamping member 54 has ahole in the middle which is normally closed by an auxiliary valve member56. This auxiliary member 56 is connected to a depending stem 58 whichextends to a point opposite the actuating plunger 30.

Referring specifically to FIG. 2, a central throat 23 is first placedinto the valve body 10. A guide ring 70 is placed around a top portionof the central throat 23, and a flow ring 72 is placed on top of theguide ring 70. The flexible rubber diaphragm 38 is then placed into thevalve body 10. A by-pass hole 42 is positioned in the flexible rubberdiaphragm 38 and a molded disc 74 is placed onto the flexible rubberdiaphragm 38. The relief valve 46 is placed through openings located inthe center of the molded disc 74 and flexible rubber diaphragm 38. Aninner cover 20 is placed over the diaphragm assembly and an outer cover18 is placed on top of the inner cover 20. As discussed in detail above,flush valves incorporating a flexible rubber diaphragm 38 have numerousdrawbacks. Accordingly, the present invention is directed to a rigidpiston 310 incorporating a solenoid 400, as shown in FIG. 3, for use ina conventional flush valve body 10.

As shown in FIGS. 3-4, the present invention includes a rigid piston 310having a disc shaped member 306 defining a central opening 313 thereinand an elongated hollow member 308 that extends from the disc shapedmember 306 of the rigid piston 310. The rigid piston 310 can also have aby-pass orifice 312 defined in the disc shaped member 306 of the rigidpiston 310. The rigid piston 310 sits directly within the hollow valvebody 10 providing a mechanism for regulating water flow through thevalve body 10.

When placed into the valve body 10, the disc shaped member 306 of therigid piston 310 sits on top of a central valve seat 124 of the outletbore 22 and the elongated hollow member 308 extends down into the outletbore 22. The disc shaped member 306 extends outward from the centralseat 124 of the outlet bore 22 to an inside annular shoulder 116 of thevalve body 10 creating a lower chamber 158 and an upper chamber 160, asshown in FIG. 5A. The lower chamber 158, located below the disc shapedmember 306 of the rigid piston 310 near the fluid inlet 12, is definedbetween the rigid piston 310, outlet bore 22, and valve body 10. Theupper chamber 160, located above the disc shaped member 306 of the rigidpiston 310, is defined between the rigid piston 310, the valve body 10,and a cylindrical cap 120 that is attached to the valve body 10 at anend opposite the fluid outlet 14.

The rigid piston 310 can have a scallop shaped flow ring 314 formaintaining a constant water flow area, such as shown in FIGS. 4 and 6.The flow ring 314 can be attached to the outer surface of the elongatedhollow member 308 of the rigid piston 310. During flushing, water flowsaround the flow ring 314 as it enters the outlet bore 22. The flow ring314 helps regulate the flow of water during flushing, which allows for aconsistent turbulent flow of water during flushing when the rigid piston310 is incorporated into the valve body 10. A consistent turbulent flowof water through the throat of a toilet helps ensure proper flushingwith a sufficient amount of water. The flow ring 314 also ensures a highvelocity of flush which allows for a quicker and more efficient flush.

Guide members 316 can also be attached to the elongated hollow member308 of the rigid piston 310 (see FIGS. 3-4). The guide members 316extend down the length of the elongated hollow member 308 of the rigidpiston 310. When the rigid piston 310 is placed into the valve body 10,the guide members 316 abut the inside wall of the outlet bore 22securing the elongated hollow member 308 of the rigid piston 310 withinthe valve body 10. The guide members 316 ride along the inside wall ofthe outlet bore 22 as the rigid piston 310 moves during operation. Thisprevents the rigid piston 310 from shifting during operation, therebymaintaining proper alignment of the rigid piston 310 within the valvebody 10 at all times. In one embodiment, the flow ring 314 is alsoattached to the guide members 316.

Referring to FIGS. 3-4, a piston seal 140 can be attached to the rigidpiston 310. As shown in FIG. 4, the piston seal 140 can have a centralopening 147 for receiving the elongated hollow member 308 of the rigidpiston 310. The piston seal 140 can also have a by-pass orifice 142. Thepiston seal 140 can be made of an elastomeric material such as rubber.The piston seal 140 is configured to fixedly engage with the rigidpiston 310. For example, as shown in FIG. 4, an undersurface 311 of thedisc shaped member 306 of the rigid piston 310 can be adapted to fixedlyengage with a sealing surface 141 of the piston seal 140. In oneembodiment, as shown in FIG. 4, the undersurface 311 of the disc shapedmember 306 of the rigid piston 310 may define cavities and the pistonseal 140 may include corresponding projections 126, such as barbedprojections, that can be placed into the cavities of the rigid piston310, thereby securing the piston seal 140 to the rigid piston 310. Incertain embodiments, the piston seal 140 is molded to the rigid piston310. The piston seal 140 can further have an annular skirt 128 thatcompletely surrounds the outer edge of the piston seal 140 (See FIG. 4).

The piston seal 140 is sized and shaped to engage and form a seal withthe valve body 10. In one embodiment, the piston seal 140 is designed toengage and form a first seal with the central valve seat 124 of theoutlet bore 22 and a second seal with a cap 120 that is attached to thevalve body 10 after the rigid piston 310 is inserted into the valve body10. For instance, once the piston seal 140 is attached to the rigidpiston 310, the rigid piston 310 and piston seal 140 can be placed intothe valve body 10. A central sealing ring 143 extending from the pistonseal 140 can be placed into the outlet bore 22 of the valve body 10 (seeFIG. 4). This engagement forms a first seal around the central valveseat 124 of the outlet bore 22 shown in FIG. 3. This helps prevent waterfrom leaking into the fluid outlet 14 from the fluid inlet 12.

The annular skirt 128 of the piston seal 140 can engage the inside of acylindrical cap 120 that is attached to the valve body 10 at an endopposite the fluid outlet 14. For example, the annular skirt 128 mayinclude a sealing edge 129 located at the bottom end of the annularskirt 128 shown in FIG. 4. As water flows through the fluid inlet 12into the lower chamber 158 (see FIG. 5A), water pushes up on the pistonseal 140. The pressure forces the annular skirt 128 surrounding thepiston seal 140 to extend out toward the cylindrical cap 120 attached tothe valve body 10. The sealing edge 129 of the annular skirt 128contacts the inside of the cylindrical cap 120 and forms a seal betweenthe piston seal 140 and the cylindrical cap 120. This second sealingengagement prevents water in the lower chamber 158 from leaking aroundthe outer portion of the rigid piston 310 into the upper chamber 160.

The dual sealing arrangement described above makes it possible to formseparate and distinct seals at two different areas in a flush valve body10 at the same time with a single piston seal 140. The use of a singlesealing member to form multiple sealing engagements in different areasat the same time, allows for an efficient sealing arrangement in a flushvalve body 10. It also allows for an easy and fast installation process.

Referring to FIGS. 3-4, the piston assembly can further include aretaining ring 90, 290. In certain embodiments, as shown in FIG. 4, theretaining ring 90 includes a by-pass orifice 92 and a central opening 91that can receive the elongated hollow member 308 of the rigid piston310. Alternatively, as shown in FIG. 3, the retaining ring 290 issmaller in size and does not have a central opening 91 to receive theelongated hollow member 308 of the rigid piston 310. FIGS. 9-12 showenlarged images of the smaller retaining ring 290 that does not have acentral opening 91 to receive the elongated hollow member 308 of therigid piston 310. As shown in FIGS. 9-12, the smaller retaining ring 290still contains the by-pass orifice 92.

In certain embodiments, the retaining ring 90, 290 can be fixedlyengaged to the piston seal 140. For example, in one embodiment shown inFIG. 4, the retaining ring 90 has a plurality of projections 114 thatcan be placed into corresponding cavities located in the piston seal140, thereby securing the retaining ring 90 to the piston seal 140.Alternatively, as shown in FIG. 13, the piston seal 140 containsprotrusions 139 that can be placed through receiving holes 291, as shownin FIGS. 9-12, in the retaining ring 290. Further, as shown in FIGS. 7and 9-13, the retaining ring 90, 290 may include a plurality of channels94 that are small in diameter, preventing large debris from entering thechannels 94.

In accordance with one embodiment of the present invention, as shown inFIGS. 3-4, a by-pass device 300 can be placed through the by-passorifices 312, 142 of the rigid piston 310 and the piston seal 140. Theby-pass device 300 includes a body having a first end 302 and a secondend 304 (see FIGS. 3-4). The second end 304 of the by-pass device 300can be placed through the by-pass orifice 312 defined in the rigidpiston 310, and the first end 302 of the by-pass device 300 can beplaced through the by-pass orifice 142 defined in the piston seal 140.Referring to FIGS. 3-4, in certain embodiments, when a retaining ring90, 290 is used, the first end 302 of the by-pass device 300 also can beplaced through a by-pass orifice 92 defined in the retaining ring 90,290.

As shown in FIG. 8, the by-pass device 300 further contains a passageway301 formed within the body of the by-pass device 300. This passageway301 connects the lower chamber 158 near the fluid inlet 12 to the upperchamber 160 located above the rigid piston 310. The passageway 301 ofthe by-pass device 300 is designed so that water can enter through atleast one opening located near the first end 302 of the by-pass device300. The water can then flow from the opening(s) located near the firstend 302, through the passageway 301, and out an opening located at thesecond end 304 of the by-pass device 300. Reference letter “B” in FIG. 8illustrates the flow of water from the lower chamber 158 to the upperchamber 160 by way of the passageway 301 of the by-pass device 300.

During assembly of one embodiment according to the present invention,the second end 304 of the by-pass device 300 is placed through theby-pass orifice 312 of the rigid piston 310. The piston seal 140 isattached to the rigid piston 310 with the first end 302 of the by-passdevice 300 being placed through the by-pass orifice 142 of the pistonseal 140. Once placed into the valve body 10, the piston seal 140 formsa seal with the central valve seat 124 of the outlet bore 22 and the cap120 that is attached to the valve body 10 after the rigid piston 310 isplaced into the valve body 10. This prevents water from entering thefluid outlet 14 and the upper chamber 160 as described above. As aresult, water from the fluid inlet 12 can only enter the upper chamber160 through the by-pass device 300.

In certain embodiments, as shown in FIGS. 3-4, a retaining ring 90, 290can be attached to the piston seal 140 and the first end 302 of theby-pass device 300 can be placed through the by- pass orifice 92 of theretaining ring 90, 290. FIG. 7 shows a bottom view of a by-pass device300 being placed through the by-pass orifice of a retaining ring 90. Asshown in FIG. 8, water flows through the channels 94 located in theretaining ring 90 and into the opening(s) located near the first end 302of the by-pass device 300, which then flows out the second end 304 ofthe by-pass device 300 and into the upper chamber 160. The channels 94are smaller in diameter than the passageway 301 of the by-pass device300. This filters out large debris, thereby preventing clogging of thepassageway 301 of the by-pass device 300.

Referring to FIG. 3, the present invention can further include anadapter 220 that can be positioned in the rigid piston 310 and extendinto the elongated hollow member 308 of the rigid piston 310. As shownin FIG. 5A, the adapter 220 engages and forms a seal with the rigidpiston 310 around the opening located in the center of the rigid piston310. This seal prevents water in the upper chamber 160 from leakingbetween the adapter 220 and rigid piston 310 and into the fluid outlet14. In certain embodiments, the adapter 220 is molded to the rigidpiston 310.

Referring to FIG. 3, a cylindrical cap 120 is placed onto the valve body10 after the rigid piston 310 and adapter 220 are installed into theflush valve body 10. The cylindrical cap 120 is placed onto the valvebody 10 next to the rigid piston 310. The cap 120 can be made of anyrigid material including various types of plastics and metals. Inaddition, the surface of the cap 120 contains the required lubricity toeasily slide onto the valve body 10. Once inserted onto the valve body10, the cylindrical cap 120 further secures the piston 310 in place andfunctions as a mechanism limiting the movement of the piston 310 to aconsistently steady axial motion within the valve body 10.

A sealing component 380, such as an O-ring or gasket, can be positionedinto the valve body 10 next to the rigid piston 310. When the cap 120 isinserted onto the valve body 10, pressure is applied to the sealingcomponent 380 contained therein, thereby forming a tight seal betweenthe valve body 10 and the cylindrical cap 120.

As shown in FIGS. 5A-5C, the cylindrical cap 120 includes a hollow stem122 that extends down from the cap 120. In certain embodiments, thecylindrical cap 120 also includes a collar 121. The hollow stem 122extends into the adapter 220 positioned in the rigid piston 310. Onceplaced into the adapter 220, the hollow stem 122 forms two seals withthe adapter 220. A first seal 150 is formed between the hollow stem 122and adapter 220 near the cylindrical cap 120, and a secondary seal 152is formed between the hollow stem 122 and adapter 220 at a locationbelow the first seal 150 (see FIG. 5C). This dual seal engagementprevents water in the upper chamber 160 from leaking between the hollowstem 122 and adapter 220 and into the fluid outlet 14.

In certain embodiments, as shown in FIGS. 5A-5C, a fitting 240, such asa bleed plug, can be used to connect a solenoid 400 to the flush valve2. Referring to FIG. 3, the fitting 240 has a first end 242 and a secondend 244. The first end 242 of the fitting 240 is connectable to theflush valve 2, such as to the collar 121 of the cap 120, and the secondend 244 is configured to receive a solenoid 400. For instance, incertain embodiments as shown in FIG. 3, the first end 242 of the fitting240 can have external threads and can be threadably connected to thecollar 121 of the cap 120, and the second end 244 of the cap 120 canhave internal threads to receive external threads on the solenoid 400.

As indicated above, in certain embodiments as shown in FIGS. 5A-5C, asolenoid 400 is attached to the fitting 240 that, in turn, is attachedto the collar 121 of the cap 120. The solenoid 400 includes a solenoidplunger 402 that is slidable within the solenoid 400, as is conventionalin many solenoids. The solenoid plunger 402 engages the inside portionof the fitting 240. The solenoid 400 allows the flush valve 2 to becontrolled electronically, such as by a conventional push-buttonactuator. In certain embodiments, the solenoid 400 is activated by aninfrared (IR) sensor. A radio frequency (RF) chip can also be built intothe flush valve 2 for wireless communication with a controller. As such,the operating handle 26 assembly previously used is removed from theflush valve body 10. As shown in FIG. 3, a cover 420 such as a cap canbe placed over the opening where the operating handle 26 assembly wasremoved. A sealing member 422, such as a washer, can be used with thecover 420.

Referring to FIG. 3, in certain embodiments, a flow restricting element440 is positioned within the flush valve 2. The flow restricting element440 controls the flow of water during operation. As shown in FIGS.5A-5C, in certain embodiments, the flow restricting element 440 ispositioned in the hollow stem 122 of the cap 120.

FIG. 5A shows the piston assembly according to one embodiment of thepresent invention incorporated into the valve body 10 while the flushvalve 2 is in a closed steady-state position. The piston seal 140attached to the rigid piston 310 engages the central valve seat 124 ofthe outlet bore 22. Water flowing into the fluid inlet 12 passes throughthe passageway 301 of the by-pass device 300, and into the upper chamber160. Water is then channeled through a passage 123 in the cap 120,through cavities in the fitting 240, and up to the solenoid 400. Becausethe solenoid plunger 402 is in a sealed position within the fitting 240,water is not allowed to flow through the hollow stem 122 of the cap 120.

As shown in FIG. 5A, the adapter 220 and hollow stem 122 of the cap 120close the opening in the center of the rigid piston 310 preventing waterfrom entering the central opening 313. The pressure in the upper chamber160 forces the piston 310 down onto the piston seal 140, which forcesthe piston seal 140 onto the central valve seat 124 forming a sealaround the outlet bore 22 so that there is no fluid communicationbetween the fluid inlet 12 and fluid outlet 14. Pressure from waterflowing through the fluid inlet 12 causes the annular skirt 128, asshown in FIGS. 3-4, to extend outward onto the inside of the cylindricalcap 120, as shown in FIG. 3. This prevents water in the lower chamber158 from entering the upper chamber 160.

In operation, as shown in FIG. 5B, when actuated, the solenoid plunger402 lifts off the fitting 240. This allows water to flow through theflow restricting element 440 and hollow stem 121, thereby relievingpressure from the upper chamber 160. The solenoid 400 remains actuatedfor a set period of time. The set period of time and the flowrestricting element 440 help control the amount of water that flows tothe fluid outlet 14.

Referring to FIG. 5C, as pressure is relieved from the upper chamber160, inlet water pressure forces the piston 310 to move axially upwardsoff of the central valve seat 124 in a direction opposite the fluidoutlet 14. The guide members 316 attached to the elongated hollow member308 of the rigid piston 310 ride along the inside wall of the outletbore 22 maintaining proper alignment of the rigid piston 310 as it movesoff the central valve seat 124.

During flushing, as shown in FIG. 5C, water flows directly from thefluid inlet 12 into the flow ring 314, which gauges the proper amount ofvolume to be flushed. The water then continues to the fluid outlet 14 inthe direction shown by reference letter “A” in FIG. 5C. As the valve isflushing, the water pressure pushing the rigid piston 310 off thecentral valve seat 124 is continuing to act on the annular skirt 128 ofthe piston seal 140. This pressure pushes the annular skirt 128 outtowards the cap 120 that is attached to the valve body 10. Thismaintains a seal between the lower chamber 158 and upper chamber 160 sothat water can only enter the upper chamber 160 through the by-passdevice 300. As discussed above, the hollow stem 122 forms two seals withthe adapter 220. A first seal 150 is formed between the hollow stem 122and adapter 220 near the cylindrical cap 120, and a secondary seal 152is formed between the hollow stem 122 and adapter 220 at a locationbelow the first seal 150. If the first seal 150 is broken, the secondaryseal 152 maintains the sealing engagement between the hollow stem 122and adapter 220.

As water flows from the inlet 12 into the outlet 14, water is alsoflowing through the by-pass device 300 into the upper chamber 160. Whenthe water pressure in the upper chamber 160 is greater than the inlet 12water pressure, the rigid piston 310 and piston seal 140 are forced backonto the central valve seat 124 in a steady axial motion with the helpof the guide members 316 so that there is no fluid communication betweenthe inlet 12 and outlet 14.

The present invention is also directed to a method of retrofitting arigid piston 310 into a flush valve body 10. Referring to FIGS. 2-4, themethod includes removing the outer cover 18 from the diaphragm flushvalve 2, and then removing the diaphragm valve assembly and operatinghandle 26 assembly from the valve body 10. Next, the rigid piston 310and piston seal 140 are attached to each other with the by-pass device300 placed within by-pass orifices 312, 142 defined in the rigid piston310 and piston seal 140. In one embodiment, a retaining ring 90, 290 isattached to the piston seal 140 and the by-pass device 300 is alsoplaced within a by-pass orifice 92 defined in the retaining ring 90,290.

The rigid piston 310 is axially mounted into the valve body 10 and ontothe central valve seat 124 of the outlet bore 22. After mounting therigid piston 310 into the valve body 10, the adapter 220 is incorporatedinto the rigid piston 310. The cylindrical cap 120 is attached to thevalve body 10 at an end opposite the flow outlet 14 with the hollow stem122 extending into the adapter 220. A sealing component 380, such as anO-ring, may also be placed into the flush valve body 10 with thecylindrical cap 120. Once placed into the adapter 220, the hollow stem122 forms two seals with the adapter 220. In certain embodiments, a flowrestricting element 440 is placed into the hollow stem 122. The firstend 242 of a fitting 240, such as a bleed plug, is connected to thecollar 121 of the cap 120. A solenoid 400 is then connected to thesecond end 244 of the fitting 240. Finally, a cover 420 can be placedover the opening where the operating handle 26 assembly was removed. Asealing member 422, such as a washer, can be used with the cover 420.

Accordingly, the present invention, which is directed to a rigid piston310 incorporating a solenoid 400 that can be used in a conventionalflush valve body 10, provides a more efficient flush that iselectronically controlled. Because the by-pass orifice 312 is larger andthe rigid piston 310 moves with a consistently steady axial movement,less water is used during the flush cycle. Further still, the presentinvention can easily be retrofitted into a conventional flush valve body10 allowing for a fast and cheap installation process.

While several embodiments of the invention were described in theforegoing detailed description, those skilled in the art may makemodifications and alterations to these embodiments without departingfrom the scope and spirit of the invention. Accordingly, the foregoingdescription is intended to be illustrative rather than restrictive.

The invention claimed is:
 1. A rigid piston assembly for use in a flushvalve, the flush valve having a valve body with a fluid inlet and afluid outlet, the rigid piston assembly comprising: a cap configured toconnect to the valve body at an end opposite the fluid outlet; a rigidpiston comprising a disc shaped member having a central opening, anelongated hollow member that is attached to and extends down from thedisc shaped member, and a piston seal; and a solenoid connectable to thecap, wherein the piston seal comprises a disc shaped body with a centralopening and an annular skirt that is adapted to expand out toward thecap connected to the valve body and form a seal with the cap, andwherein the annular skirt extends around an outside perimeter of boththe piston seal and the disc shaped member of the rigid piston.
 2. Therigid piston assembly according to claim 1, wherein at least a portionof the piston seal is attached directly to at least a portion of thedisc shaped member of the rigid piston.
 3. The rigid piston assemblyaccording to claim 1, wherein the piston seal is molded to the rigidpiston.
 4. The rigid piston assembly according to claim 1, wherein theflush valve further comprises (1) an infrared sensor formed therein toactivate the solenoid, and/or (2) a radio frequency chip formed thereinfor wireless communication with a controller.
 5. The rigid pistonassembly according to claim 1, wherein the rigid piston furthercomprises guide members that maintain an alignment of the rigid pistonwithin the valve during operation.
 6. The rigid piston assemblyaccording to claim 5, wherein the guide members extend down the lengthof the elongated hollow member of the rigid piston.
 7. The rigid pistonassembly according to claim 1, wherein the rigid piston furthercomprises a flow ring that gauges the amount of water to be flushedduring operation.
 8. The rigid piston assembly according to claim 7,wherein the flow ring is attached to an outer surface of the elongatedhollow member of the rigid piston.
 9. The rigid piston assemblyaccording to claim 1, wherein the piston seal further comprises acentral sealing ring extending out from and surrounding an edge of thecentral opening.
 10. The rigid piston assembly according to claim 1,wherein the piston seal further comprises a by-pass orifice.
 11. A flushvalve for a plumbing fixture comprising: a) a fluid inlet in fluidcommunication with a fluid source; b) a fluid outlet in fluidcommunication with a plumbing fixture; c) a cap positioned at an endopposite the fluid outlet; and d) a piston valve for regulating fluidflow between the fluid inlet and the fluid outlet, the piston valvecomprising: a rigid piston comprising a disc shaped member having acentral opening, an elongated hollow member that is attached to andextends down from the disc shaped member, and a piston seal; and e) asolenoid connected to the cap, wherein the piston seal comprises a discshaped body with a central opening and an annular skirt that is adaptedto expand out toward the cap connected to the valve body and form a sealwith the cap, and wherein the annular skirt extends around an outsideperimeter of both the piston seal and the disc shaped member of therigid piston.
 12. The flush valve according to claim 11, wherein atleast a portion of the piston seal is attached directly to at least aportion of the disc shaped member of the rigid piston.
 13. The flushvalve according to claim 11, wherein the piston seal is molded to therigid piston.
 14. The flush valve according to claim 11, wherein theflush valve further comprises (1) an infrared sensor formed therein toactivate the solenoid, and/or (2) a radio frequency chip formed thereinfor wireless communication with a controller.
 15. The flush valveaccording to claim 11, wherein the piston seal further comprises acentral sealing ring extending out from and surrounding an edge of thecentral opening.
 16. The flush valve according to claim 11, wherein therigid piston further comprises guide members that maintain an alignmentof the rigid piston within the valve during operation.
 17. The flushvalve according to claim 16, wherein the guide members extend down thelength of the elongated hollow member of the rigid piston
 18. The flushvalve according to claim 11, wherein the rigid piston further comprisesa flow ring that gauges the amount of water to be flushed duringoperation.
 19. The flush valve according to claim 18, wherein the flowring is attached to an outer surface of the elongated hollow member ofthe rigid piston.
 20. The flush valve according to claim 11, wherein thepiston seal further comprises a by-pass orifice.